This invention relates to the art of orthodontics, and more particularly to an improved orthodontic facebow and method for applying facebows in orthodontic procedures, facilitating the use of a single size of facebow for most patients.
Among the appliances evolved for effecting desired orthodontic corrections, a so-called "facebow" has been evolved in which an inner bow is provided for positioning along the upper or lower teeth of the patient, so as to provide means for applying desired forces to these teeth to effect desired orthodontic action. The application of force to the teeth via the inner bow is obtained by connecting the inner bow to an outer bow, extending along the cheeks of a patient and coupled to a head or cervical gear, such for example as an elastic member stretched over the rear of the head or neck respectively of the patient. The inner bow is coupled to the teeth by extending the ends of the relatively U-shaped inner bow through retaining tubes attached to the teeth of the patient, and by means of hooks on the outer bow to the head gear or cervical gear.
Such extra-oral force facebows are widely used. Among the problems arising in their use, is that the orthodontist is required to stock an inventory of a variety of differently sized facebows to accommodate a great variety of different patients to whom the facebows are to be applied. Aside from the increase in cost resulting from the need to maintain an inventory of differently sized facebows, the delay in selecting a properly sized facebow, and the increased storage facility which must be provided, the use of standard size bows does not necessarily result in a precise desired fitting of the inner bow to the teeth of the patient, since there may not be a precise corelationship between the dimensions of the facebows in stock and the arch of the patient's mouth.
Further, in positioning the facebow, it is necessary to guide the free ends of the inner bow into the molar retaining tubes. The dentist positioning the archwire generally has no problem since he can see what he is doing. However, facebows are generally intended for use in the privacy of the home, since the appearance of the facebow and associated cervical or head band is not generally regarded as esthetically acceptable in most social situations. The patient thus must apply and remove the facebow. Patients often find it difficult to manipulate the bow into desired position on the teeth, since they must be either working by feel or by a mirror image, and find it difficult to guide the free ends of the inner bow into the molar tubes.
It is with the above problems in mind that the present improved facebow has been evolved, serving to permit a single size of facebow to be employed almost universally on different patients, and further to facilitate the ease with which the facebow may be applied and removed by orthodontist and patient.
It is accordingly among the primary objects of the invention to provide an improved facebow design which may be applied relatively universally in patients of different oral dimensions.
A further object of the invention is to provide a facebow design that can minimize the inventory maintenance requirements of an orthodontist.
Another object of the invention is to provide an improved facebow which can be relatively easily positioned in the mouth of the wearer either by the orthodontist or the patient.
Another object of the invention is to provide an improved facebow which can be readily adjusted as the desired correction takes place, without requiring the use of different additional facebows.
An additional object of the invention is to allow the orthodontist greater flexibility in treatment strategies by increasing availability of placement sites for corrective attachments.
A further object of the invention is to provide a facebow permitting the selective application of unilateral pressure to the dental arch of the patient.